“…that stimulates the sensation of pain (Cavanaugh, 1995;Cavanaugh et al, 1997;Rempel et al, 1999;Siddall and Cousins, 1997). Inflammatory cytokines can increase Prostaglandin E 2 synthesis which acts at both peripheral free nerve endings of sensory neurons and at central sites within the spinal cord and brain to increase pain sensation (Peters et al, 1990).…”